This proposal seeks to explore the hypothesis that odorants entering the nasal cavity generate specific patterns of mucosal activity that depend both on the inherent differences in sensitivity of distributed receptor cells and on imposed patterns of differential airflow. Further this hypothesis states that these spatially different patterns of epithelial activity generate spatially different patterns of bulbar activity and that these patterns relate to the behavioral output of the system. To carry out these correlations the PI proposes to use a combination of modeling the aerodynamic properties of the nasal cavity, voltage-sensitive dye recording from the olfactory epithelium and bulb, and behavioral testing of rats. The specific protocols he proposes to test at each of these levels are: 1) use of stepwise binary odorant mixtures; 2) use of cross adapting odorant sets; 3) use of homologous series of odorous compounds; and 4) manipulation of the flow path and direction of the stimuli.